extdbg

by Eugene Duboviy

Extended debugging python utilities

Installation:

Install from PyPI:

pip install extdbg

Or using alternative command:

pip install https://github.com/duboviy/extdbg/archive/master.zip

Or from source use:

python setup.py install

Supported python versions

• 2.7
• 3.3
• 3.4
• 3.5
• PyPy

PyPI

• Package
• Documentation

Contents

from extdbg import ... (see variants in list below)

• init_except_hook - initialise extended traceback hook with local variables in exception message
• add_watcher_attribute(name, watch_get=False) - when called within some class (for example add_watcher_attribute('name')) - instances of that class will log every change to the attribute. Also tracks every access to attribute if watch_get is True.
• where_is(object) - return location of the object definition in code.
• from_where_called() - return location in code from where function which calls this is called
• threaded - allow you to decorate a function in your Python code, making it run in a separate thread
• get_func_calls - return all function calls from a python file
• public and internal - allow you to use additional context decorators (like public and private in other languages)
• hackable_properties - properties mock setter. Use this module to mock/stub any property of New Style Class
• watch_for_output - log location in code where some output is performed
• bound_func - bind any function/lambda as instance's method
• save_object and load_object - pickle/unpickle objects in/from files
• enable_debug - use on remote process to debug it using pycharm remote server run

... and many other features

Basic usage examples

• init_except_hook - initialise extended traceback hook with local variables in exception message

from extdbg import init_except_hook


init_except_hook()

def test(a, b):
    a / b

test(1, 0)

• where_is(object) - return location of the object definition in code

from extdbg import where_is


location = where_is(where_is)

expected_filename = "navigate.py"
expected_line_no = 17

assert location.filename.endswith(expected_filename)
assert location.line_no == expected_line_no

• from_where_called() - return location in code from where function which calls this is called

from extdbg import from_where_called


def f2():
    print(from_where_called())

def f1():
    f2()
    
f1()

• threaded - allow you to decorate a function in your Python code, making it run in a separate thread

from extdbg import threaded


def fib(n):
    if n < 2:
        return n
    return fib(n-2) + fib(n-1)

print(fib(35))

@threaded(daemon=True)
def _fib(n):
    if n < 2:
        return n
    return fib(n-2) + fib(n-1)

print(_fib(35))

• get_func_calls - return all function calls from a python file

import ast

from extdbg import get_func_calls


filename = __file__
tree = ast.parse(open(__file__).read())
print(get_func_calls(tree))

• public and internal - allow you to use additional context decorators (like public and private in other languages). You can use decorator to wrap your code:

from extdbg import public, internal


class A(object):

    @internal
    def m1(self):
        pass

    @public
    def m2(self):
        self.m1()

a = A()
a.m1()  # can't call API m1 is marked as internal!
a.m2()

• hackable_properties - properties mock setter. Use this module to mock/stub any property of New Style Class

from extdbg import hackable_properties, ValueWrapper


class NewStyleCls(object):
    @property
    def prop_2_mock(self):
        raise RuntimeError("Unmocked property!")


@hackable_properties
class NewStyleClsMocked(NewStyleCls):
    def __init__(self, *args, **kwargs):
        super(NewStyleClsMocked, self).__init__(*args, **kwargs)
        self.prop_2_mock = ValueWrapper("MOCKING_PROP_VALUE")

mockable_cls = NewStyleClsMocked()
assert mockable_cls.prop_2_mock == "MOCKING_PROP_VALUE"

• watch_for_output(condition=lambda x: True, stream='stdout') - log location in code where some output is performed

import unittest

from mock import Mock, patch


class TestWatchForOutput(unittest.TestCase):

    def test_works(self):
        from extdbg import watch_for_output

        mock_stdout = Mock()
        output = []

        def write(txt):
            output.append(txt)

        mock_stdout.write = write
        with patch('sys.stdout', mock_stdout):
            watch_for_output(lambda s: 'yes' in s)
            print('yes')

        self.assertIn('yes', output)

• bound_func - bind any function/lambda as instance's method

import unittest
import inspect

from mock import Mock, patch


class TestBoundFunc(unittest.TestCase):

    def test_works(self):
        from extdbg import bound_func
        # Example of usage
        class Cls2Bound:
            pass

        instance2Bound = Cls2Bound()

        def func(*args, **kwargs):
            print(args, kwargs)

        l = lambda *args, **kwargs: None

        # bound method Cls2Bound.func
        bound_method1 = bound_func(func, instance2Bound, Cls2Bound)
        # bound method Cls2Bound.<lambda>
        bound_method2 = bound_func(l, instance2Bound, Cls2Bound)

        self.assertTrue(inspect.ismethod(bound_method1))
        self.assertTrue(inspect.ismethod(bound_method2))

• enable_debug - use on remote process to debug it using pycharm remote server run

from extdbg import enable_debug


enable_debug("/home/<username>/pydev/debug-eggs/pycharm-debug.egg", 'localhost')

License

MIT licensed library. See LICENSE.txt for details.

Contributing

If you have suggestions for improving the extdbg, please open an issue or pull request on GitHub.

Badges